4. The heat of fusion of a
substance is
80 J/g. How
much energy
is required to
melt 25 g of
the
substance?
A. 2J
B. 25 J
C. 80 J
D. 2 kJ

It is 2 KJ

It is because the formula is :

q=m∆Hf

where m is the mass and ∆Hf is the heat fusion.

So, we get:

q=80×25

q=2000J or 2 KJ

nanotechnology is a powerful tool in biomaterials research as it creates numerous possibilities for the engineering of functional molecules. nano-bio refers to projected ability to incorporate biomimicry into various materials at nanoscale.  

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons